[Graph]: set the default value properly in test_eigen.
[Graph]: set the default value properly in test_eigen.

flashxio/FlashX,icoming/FlashGraph,flashxio/FlashX,flashxio/FlashX,zheng-da/FlashX,flashxio/FlashX,zheng-da/FlashX,flashxio/FlashX,zheng-da/FlashX,flashxio/FlashX,icoming/FlashX,icoming/FlashX,icoming/FlashGraph,icoming/FlashX,icoming/FlashGraph,icoming/FlashX,icoming/FlashGraph,zheng-da/FlashX,zheng-da/FlashX,icoming/FlashX,icoming/FlashGraph